There is a current trend toward the development and use of privately-owned pay station telephones. This has recently been made possible by the deregulation of such equipment.
While pay station telephones have been widely used for a long period of time, their ownership has been in the exclusive control of the major telephone operating companies. These telephone companies maintained complete control over the manufacture of pay station telephones, the installation and the distribution of revenue generated thereby. All the ancillary services attendant with a pay station telephone, such as operator services, were also supplied and controlled by the telephone operating companies.
Because of the unique nature of pay station telephone revenue collection, special communication lines and central office equipment were provided to administer the mechanics of the proper coin collection and to enable the completion of a telephone call. Because the initiation of this type of telephone call is significantly different from that of the business or residential call, the central office equipment was necessary to transmit coin collect and coin return voltages to the pay station telephone. The pay station telephone communication lines were generally not available for use by owners of privately-operated pay station telephones. Private pay station owners generally used special class marked trunks which were similar to standard business lines, but which gave an indication to an operator that the telephone was of the pay station type. Charges for making calls could then be handled accordingly. Such specialized class marked trunks are commonly known as "COCOT" trunks, an acronym for customer owned coin operated telephone.
As an alternative to the foregoing, "smart" pay station telephones have been developed for use with the conventional telephone business line. The drawback generally experienced with that approach is the user is required to learn a new method of operating the telephone. The difficulty with learning a new procedure different from a previously known and standard procedure is apparent.
Owing to the recent developments in ownership and control of pay station telephones, such apparatus may now be privately owned. This has given rise to the sale on the open market of new, reconstructed and refurbished pay station telephone sets. While the proprietor of a privately owned pay station telephone set can gain the benefit of the revenues generated therefrom, the use of specialized telecommunication services and equipment of others is still required. For example, the owners of privately held pay station telephones may subscribe to an operator service corporation to provide switchboard assistance to pay station callers. Secondly, in order to provide appropriate coin accounting, the class-marked or COCOT trunk is the only type of telephone line which can operate with the conventionally available pay station telephone.
From the foregoing, it can be seen that a need exists for improved pay station telephone equipment which can provide a sophisticated level of service to calling parties, and a higher degree of profitability to the owner. There is an associated need for a sophisticated pay station interface which is operable in conjunction with a standard pay station telephone and a standard business telephone line, and which is capable of autonomous operation so that routine calls can be completed without the need of special supervision signals associated with the COCOT trunk.